Effect of vitamin D3 and 1,25(OH)2D3 on growth of neoplastically derived cell lines and their alkaline phosphatase activity.

Inhibitory effects of 1,25(OH)2D3 and D3 on growth of four neoplastically derived cells were observed in human acute leukemia cell culture CEM-C-1 and CEM-C-7, human cervical carcinoma cell lines C-4-1 and human epithelioid carcinoma cells of cervix HeLa S3K. Concurrently, in dexamethasone-responsive cells C-4-1 and HeLa S3K there was a 1,25(OH)2D3 and D3 induced elevation of alkaline phosphatase with 1,25(OH)2D3 showing the greater effects. It is supposed that vitamins D3-induced alkaline phosphatase activity in malignant cells, which is proposed to be a possible marker of cell differentiation, can be associated with the membrane effects of these vitamins.

Effects of vitamin D3 and ecdysterone on free-radical lipid peroxidation.

Free-radical-induced lipid peroxidation was studied in vivo by measuring chemiluminescence of tissues from vitamin D-deficit animals before and after peroral administration of low-molecular-weight biological steroids vitamin D3 (cholecalciferol) and ecdysterone. The kinetics of lipid chemiluminescence in model systems in vitro were determined in blood serum and microsomal and mitochondrial fractions of the liver. Vitamin D3 (cholecalciferol) and ecdysterone displayed antiradical properties; the latter was more potent in this respect.